Influence of cement content on the thermal properties of compressed earth blocks (CEB) in the dry state

Abstract

The Compressed Earth Block (CEBs) is one of the kinds of building materials which stabilized by cement. Soil is a basic component, a renewable, non-toxic and natural resource. Samples must be stabilized with a limited percentage of cement so that samples do not lose their natural properties including thermal comfort and on other hand offer high mechanical resistance. The objective of this work is to study the effect of cement content on thermal behavior of the building material of CEBs in the dry state, by studying variation of temperature with time, and measuring thermal conductivity and the specific heat, with respect to the various cement ratios added to the samples. This study is mainly an experimental and numerical, to determine how the thermal behavior evolves with the cement content in the samples CEBs. The soil was extracted from the famous city Fez in Morocco, Fez is known for its several historical monuments and buildings. After determining its granulometry and other specific characteristics, the CEBs are made by mixing soil with cement. The samples are put in plastic bags for two weeks, then removed the plastic bags from the samples and let them to dry again for an additional two weeks away from direct sun. The samples CEBs are taken cylindrical form (8 cm diameter with an average height of 12 cm). The experimental method consists of a hot ring for which a numerical modelization was developed to fit the mathematical equations of heat diffusion and the boundary conditions. For the numerical model Bouabid and Cherraj have developed numerical model which allow, with a good accuracy, to quantify the evolution of the thermal behavior of the earth material in function of cement content. Indeed, the study provides information on the influence of the cement percentage on the thermal behavior of the samples CEBs, the thermal behavior of samples increase with increase cement content.

Condutividade térmica do material construtivo solo-cimento: um estudo bibliométrico

“…ENTAC2022 -Ambiente Construído: Resiliente e Sustentável 9 Com relação a influência nas propriedades térmicas causada pela adição de cimento no solo, ainda há controvérsias. Enquanto Zhang et al [54] demonstram por meio de ensaios que não há uma correlação visível entre a porcentagem de cimento presente no bloco e a sua condutividade térmica, Zakham et al [52] apontam que maiores porcentagens de cimento na amostra acarretam em um aumento da condutividade térmica dos BTC.…”

Soil-cement blocks: a sustainable alternative for the reuse of industrial solid waste

“…According to Ashour et al (2015), the current global concerns arose from extensive environmental problems, together with the accelerated pace of technological advancement in the industry, especially in construction, and, with that, the interest in the development of alternative building materials gained space, especially materials made of earth. According to Zakham et al (2018), stabilized soil blocks help improve the construction energy efficiency, mainly because they have low thermal conductivity. In this way, it is possible to use them to improve the thermal and acoustic insulation in buildings.…”

Comparative Study of Thermal Comfort Induced from Masonry Made of Stabilized Compressed Earth Block vs Conventional Cementitious Material

“…Among various earth blocks based building materials, compressed earth blocks (CEB) represent 56% [4]. Cement based materials have worse energy efficiency than earthen materials [5] [6] [7] [8]. In addition, the process of production of cement based materials is very polluting, without mentioning their relatively high cost [8].…”

“…Cement based materials have worse energy efficiency than earthen materials [5] [6] [7] [8]. In addition, the process of production of cement based materials is very polluting, without mentioning their relatively high cost [8]. The choice of CEB is guided by the fact that they are known to be more ecological than cement blocks or concrete [9] [10] [11] [12].…”

“…In recent decades, some studies tried to evaluate the thermal comfort in building gained from constructing with cement or lime stabilized earth blocks [8]. Thermal comfort is defined by ASHRAE [14] by "that condition of mind which expresses satisfaction with the thermal environment and is assessed by subjective evaluation".…”